The investigation, led by the Ministry of Health's director of mental health Dr John Crawshaw, found Waikato's services were well-managed but under considerable pressure.

"There are families, and their loved ones with mental illness, who have been distressed by these incidents and by subsequent publicity," said Dr Crawshaw. "One incident resulted in a tragic death, and the Ministry extends its sympathy to those affected."

The report found an appropriate model of care was already in place, but made recommendations aimed at increasing public confidence in the services provided.

As well as addressing staff shortages, it also recommended:

Dr Crawshaw said the DHB has already made changes to its mental health services, including appointing an executive director of mental health services in February, adjusting its training and management model, strengthening clinical governance and engaging with the community more.